Ore Genesis of the Kalatongke Cu-Ni Sulfide Deposits, Western China: Constraints from Volatile Chemical and Carbon Isotopic Compositions

The Kalatongke Cu-Ni sulfide deposits located in the East Junggar terrane, northern Xinjiang, western China are the largest magmatic sulfide deposits in the Central Asian Orogenic Belt （CAOB）. The chemical and carbon isotopic compositions of the volatiles trapped in olivine, pyroxene and sulfide mineral separates were analyzed by vacuum stepwise-heating mass spectrometry. The results show that the released volatiles are concentrated at three temperature intervals of 200-400°C, 400-900°C and 900-1200°C. The released volatiles from silicate mineral separates at 400-900°C and 900-1200°C have similar chemical and carbon isotopic compositions, which are mainly composed of H2O （av. ~92 mol%） with minor H2, CO2, H2S and SO2, and they are likely associated with the ore-forming magmatic volatiles. Light δ13CCO2 values （from -20.86‰ to -12.85‰） of pyroxene indicate crustal contamination occurred prior to or synchronous with pyroxene crystallization of mantlederived ore-forming magma. The elevated contents of H2 and H2O in the olivine and pyroxene suggest a deep mantle-originated ore-forming volatile mixed with aqueous volatiles from recycled subducted slab. High contents of CO2 in the ore-forming magma volatiles led to an increase in oxygen fugacity, and thereby reduced the solubility of sulfur in the magma, then triggered sulfur saturation followed by sulfide melt segregation; CO2 contents correlated with Cu contents in the whole rocks suggest that a supercritical state of CO2 in the ore-forming magma system under high temperature and pressure conditions might play a key role in the assemblage of huge Cu and Ni elements. The volatiles released from constituent minerals of intrusion 1# have more CO2 and SO2 oxidized gases, higher CO2/CH4 and SO2/H2S ratios and lighter δ13CCO2 than those of intrusions 2# and 3#. This combination suggests that the higher oxidation state of the volatiles in intrusion 1# than intrusions 2# and 3#, which could be one of key ore-forming factors for large amounts of ores and high contents of Cu and Ni in intrusion 1#. The volatiles released at 200-400°C are dominated by H2O with minor CO2, N2＋CO and SO2, with δ13CCO2 values （-25.66‰ to -22.98‰） within the crustal ranges, and are considered to be related to secondary tectonic-hydrothermal activities.

Analysis of volatile chemical components of Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.

Physicochemical properties and volatile components of hempseed oils in Bama region

A comparison study has been performed in hempseed oils (HSO) extracted from different cultivars in Bama region. Squeezing properties, chemical compositions, thermal stability and flavor profile of pressed HSO were determined in this study. Results indicated that there were no significant differences in crude fat, protein, fiber of different hempseeds and fatty acid composition in HSOs. Hempseeds with small size and dark-colored peel have lower squeezing oil yield than big ones. Average content of total phytosterol, tocopherol and phenol in HSO from small seeds were 872.0 mg/100 g, 124.1 mg/100 g and 15.5 mg SA/100 g respectively. Thermal oxidation by differential scanning calorimetry (DSC) revealed three step oxidation of HSO with mean onset and oxidation temperature at 124oC and 135-315oC. Oxidation temperature of HSO from small seeds was higher than that from big seeds (big size and light-colored peel). Main volatile ingredients in HSO contained 11 kinds of monoterpene and 7 kinds of sesquiterpene. Volatile terpene content in HSO from small seeds was nearly 30% higher than that of big seeds. Quality of HSO with different peel feature has significant difference in squeezing yield, thermal stability and volatile flavors. This work may be useful to produce high quality hempseed oils through quality evaluation.

Experimental Study on Chemical Looping With Oxygen Uncoupling Using Copper Based Oxygen Carrier and Different Volatiles Contained Coal Chars

采用溶胶一凝胶法制备CuO／CuAl204氧载体，研究了该氧载体在N2气氛下的释氧性能，发现氧载体774℃时开始释氧，且随着温度的升高氧气含量不断升高。随后，在流化床反应器中研究了挥发分含量不同的6种煤焦的化学链氧解耦燃烧（chemicalloopingwithoxygenuncoupling，CLOU）特性，结果表明，挥发分含量的增加和温度的升高均会加速煤焦燃烧，煤焦中碳元素转化率达到95％所需要的时间随着挥发分含量及温度的升高不断减少，相应的碳的平均转化率也不断增加；然而，较高的挥发分含量和反应温度都会导致CO2捕集率的下降。对于挥发分含量低的高平煤焦和东欢坨煤焦，C02捕集率超过99％，而对于挥发分高的胜利褐煤焦，C02捕集率不足95％。

Theoretical assessment of hydrogen production and multicycle energy conversion via solar thermochemical cycle based on nonvolatile SnO2

A kind of solar thermochemical cycle based on methanothermal reduction of SnO2 is proposed for H2 and CO production. We find that the oxygen release capacity and thermodynamic driven force for methanothermal reduction of SnO2 are large, and suggest CH4 :SnO2 = 2:1 as the feasible reduction condition for achieving high purities of syngas and avoiding vaporization of produced Sn. Subsequently, the amount of H2 and energetic upgrade factors under different oxidation conditions are compared, in which excess water vapor is found beneficial for hydrogen production and fuel energetic upgradation. Moreover, the effect of incom plete recovery of SnO2 on the subsequent cycle is underscored and explained. After accounting for factors such as isothermal operation and cycle stability, CH4 :SnO2 = 2:1 and H2O:Sn = 4:1 are suggested for highest solar-to-fuel efficiency of 46.1% at nonisothermal condition, where the reduction and oxidation temperature are 1400 and 600 K, respectively.

Analysis of Volatile Chemical Constituents in Callistemon rigidus Flowers by GC-MS

Volatile components of Callistemon rigidus were analyzed by headspace solid phase microextraction-gas chromatography/mass spectrometry.The results showed that 34 volatile components,including alkenes,esters,alcohols,and a small amount of acids,heterocycles and alkanes,were identified from C.rigidus flowers.The main components were eucalyptol,aspidinol,terpilenol,vanillylacetone,α-phellandrene,4-pyran-4-1,2,3-dihydro-3,5-dihydroxy-6-methyl,pinene,3-methylcatechol,naphthalene,(+)-limonene,7-methylxanthine and (+)-aromadendrene,the contents of which were 35.39%,10.09%,8.86%,4.51%,3.25%,2.81%,2.75%,2.43%,2.29%,1.3%,1.12% and 1.07%,respectively,all of which accounted for 75.69% of the total relative content.Monoterpenoids are the main components of various types of essential oils.This study provides a theoretical basis for the deep processing of this variety.

Characteristics of physico-chemical properties, volatile compounds and free fatty acid profiles of commercial set-type Turkish yoghurts

Ten most popular brands of commercial Turkish set-type yoghurts were collected from local retail outlets in Hatay, Turkey for two separate periods, and analyzed for basic nutrients, physico-chemical properties, volatile aroma compounds and free fatty acid profiles to compare their differences among the yoghurt products. The results showed that there were significant differences (P<0.05, 0.01, or 0.001) and variations in physico-chemical indices, volatile aroma compounds and volatile free fatty acid profiles among the yoghurt brands, which ultimately influence the flavor quality of the product. Acetaldehyde was predominant volatile compound in yoghurts, which followed by acetone, acetoin, diacetyl and ethanol. The level of diacetly was inversely related to titratable acidity, acetaldehyde and ethanoic acid. From ketones with high carbones 2-undecanone and 2-pentadecanone were higher than 2-butanone, 2-nanonane and 2-tridecanone. These ketones are related to fat content of yoghurt. Among short chain free fatty acids, ethanoic (acetic) acid was the most abundant in yoghurts, followed by hexanoic, octanoic and butanoic acids. These differences in detected chemical compositions of volatile compounds and free fatty acids would be applicable to predict flavor, nutritional value, quality control or shelf-life of the commmercial set-type Turkish yoghurts.

Characteristics and chemical reactivity of biogenic volatile organic compounds from dominant forest species in the Jing-Jin-Ji area,China

Background:Biogenic volatile organic compounds(BVOCs)play an essential role in tropospheric atmospheric chemical reactions.There are few studies conducted on BVOCs emission of dominant forest species in the Jing-Jin-Ji area of China.Based on the field survey,forest resources data and the measured standard emission factors,the Guenther model developed in 1993(G93)was applied in this paper to estimate the emission of BVOCs from several dominant forest species(Platycladus orientalis,Quercus variabilis,Betula platyphylla,Populus tomentosa,Pinus tabuliformis,Robinia pseudoacacia,Ulmus pumila,Salix babylonica and Larix gmelinii)in the Jing-Jin-Ji area in 2017.Then the spatiotemporal emission characteristics and atmospheric chemical reactivity of these species were extensively evaluated.Results:The results showed that the total annual BVOCs emission was estimated to be 70.8 Gg C·year^(−1),consisting 40.5%(28.7 Gg C·year^(−1))of isoprene,36.0%(25.5 Gg C·year^(−1))of monoterpenes and 23.4%(16.6 Gg C·year^(−1))of other VOCs.The emissions from Platycladus orientalis,Quercus variabilis,Populus tomentosa and Pinus tabulaeformis contributed 56.1%,41.2%,36.0% and 31.1%,respectively.The total BVOCs emission from the Jing-Jin-Ji area accounted for 61.9% and 1.8%in summer and winter,respectively.Up to 28.8% of emission was detected from Chengde followed by Beijing with 24.9%,that mainly distributed in the Taihang Mountains and the Yanshan Mountains.Additionally,the Robinia pseudoacacia,Populus tomentosa,Quercus variabilis,and Pinus tabulaeformis contributed mainly to BVOCs reaction activity.Conclusions:The BVOCs emission peaked in summer(June,July,and August)and bottomed out in winter(December,January,and February).Chengde contributed the most,followed by Beijing.Platycladus orientalis,Quercus variabilis,Populus tomentosa,Pinus tabulaeformis and Robinia pseudoacacia represent the primary contributors to BVOCs emission and atmospheric reactivity,hence the planting of these species should be reduced.

Analysis of the Volatile Chemicals of Longjing Tea from Different Production Locations Using Electronic Nose

Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.

Volatile oil from Litsea lancilimba Merr.: a review of its chemical structure and biological activity

Litsea lancilimba Merr.is a Cinnamomum plant of Lauraceae.Phytochemical investigations of the Litsea lancilimba Merr.have resulted in the isolation of Volatile oil,flavonoid glycosides,tannins,alkaloids,lignans,organic acids and so on.Studies have showed that volatile oil is the main chemical component.Recent trials have demonstrated the efficacy of Litsea lancilimba Merr.in strengthening the function of stomach.The fruits have also been demonstrated to possess anti-inflammatory and bacteriostatic activities.This review deals mainly with the chemical structure and biological activities of Litsea lancilimba Merr.oil.

Extreme learning with chemical reaction optimization for stock volatility prediction

Extreme learning machine(ELM)allows for fast learning and better generalization performance than conventional gradient-based learning.However,the possible inclusion of non-optimal weight and bias due to random selection and the need for more hidden neurons adversely influence network usability.Further,choosing the optimal number of hidden nodes for a network usually requires intensive human intervention,which may lead to an ill-conditioned situation.In this context,chemical reaction optimization(CRO)is a meta-heuristic paradigm with increased success in a large number of application areas.It is characterized by faster convergence capability and requires fewer tunable parameters.This study develops a learning framework combining the advantages of ELM and CRO,called extreme learning with chemical reaction optimization(ELCRO).ELCRO simultaneously optimizes the weight and bias vector and number of hidden neurons of a single layer feed-forward neural network without compromising prediction accuracy.We evaluate its performance by predicting the daily volatility and closing prices of BSE indices.Additionally,its performance is compared with three other similarly developed models—ELM based on particle swarm optimization,genetic algorithm,and gradient descent—and find the performance of the proposed algorithm superior.Wilcoxon signed-rank and Diebold–Mariano tests are then conducted to verify the statistical significance of the proposed model.Hence,this model can be used as a promising tool for financial forecasting.

Effect of the chemical forms of selenium on its volatilization from soils in Chinese low-selenium belt

Bio-availability of different forms of selenium and its rate of volatilization from soils in Chinese low-selenium belt were examined. Adding directly solutions of either inorganic or organic selenium compounds to soil could only slightly increase the rate of selenium volatilization from soil. Volatilization of selenium from soil was largely enhanced when certain nutritional solutions along with selenium compounds were added. Garlic water extract and seleno-amino acids, i.e., seleno-methionine and seleno-cysteine, were found more effective for their bio-availability to the volatilization process. Under laboratory simulating conditions, the volatilization rate of selenium from different types of soils in Chinese low-selenium belt was found in the range of 0.10-0.27 ng.kg-1 soil.day-1 over a 17 days period, generally followed by a decline with time of incubation.

Real-time,single-particle chemical composition,volatility and mixing state measurements of urban aerosol particles in southwest China

To investigate the volatility of atmospheric particulates and the evolution of other particulate properties(chemical composition,particle size distribution and mixing state)with temperature,a thermodenuder coupled with a single particle aerosol mass spectrometer was used to conduct continuous observations of atmospheric fine particles in Chengdu,southwest China.Because of their complex sources and secondary reaction processes,the average mass spectra of single particles contained a variety of chemical components(including organic,inorganic and metal species).When the temperature rose from room temperature to280℃,the relative areas of volatile and semi-volatile components decreased,while the relative areas of less or non-volatile components increased.Most(>80%)nitrate and sulfate existed in the form of NH_(4)NO_(3)and(NH_(4))_(2)SO_(4),and their volatilization temperatures were50–100℃and 150–280℃,respectively.The contribution of biomass burning(BB)and vehicle emission(VE)particles increased significantly at 280℃,which emphasized the important role of regional biomass burning and local motor vehicle emissions to the core of particles.With the increase in temperature,the particle size of the particles coated with volatile or semi-volatile components was reduced,and their mixing with secondary inorganic components was significantly weakened.The formation of K-nitrate(KNO_(3))and K-sulfate(KSO_(4))particles was dominated by liquid-phase processes and photochemical reactions,respectively.Reducing KNO_(3)and BB particles is the key to improving visibility.These new results are helpful towards better understanding the initial sources,pollution formation mechanisms and climatic effects of fine particulate matter in this megacity in southwest China.

Effects of Leptocybe invasa Damage on Chemical Components of Eucalyptus

[Objective] The aim was to illustrate the relation between Leptocybe invasa and eucalyptus, so as to provide the basis for scientific control of L. invasa. [Method] The chemical components of eucalyptus were extracted by solid phase micro-extraction （SPME） technique and ethanol extraction method, and detected by gas chromatograph-mass spectrometer. The relative contents of various components were determined by area normalization. [Result] When eucalyptus was damaged by L. invasa, not only some substances disappeared, but also new substances were induced. Among 4 induced volatiles, the content of terpinolene was the highest of 37.66%. Eight new chemical substances were also detected from the ethanol extract of damaged leaves, and the content of 3-phenyl-2-propenyl phenpropionate was the highest of 30.95%.[Conclusion] The damage caused by L. invasa had obvious effect on composition and contents of chemical components of eucalyptus.

Analysis of Volatile Components in Fresh Fruit of Morinda citrifolia L.from Different Origins Based on HS-SPME-GC/MS

[Objectives]This study was conducted to clarify the differences of volatile components in fresh fruit of Morinda citrifolia L.from different origins.[Methods]The method of HS-SPME-GC/MS detection was used to determine the volatile chemical components in fresh fruit of M.citrifolia.[Results]52,52 and 45 volatile components were identified from the fresh fruit of M.citrifolia from Xisha,Wanning and Haikou,respectively.Among them,the number and content of the identified esters were relatively high,mainly methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbuten-2-enyl caprylate,methyl caproate,and ethyl caproate.There were also fatty acids,alcohols,phenols,ketones,aldehydes and other substances.There were 33 common ingredients in the fruit from the three origins,mainly including caprylic acid,caproic acid,capric acid,methyl caprylate,ethyl caprylate,4-pentenyl caproate,3-methylbutene-2-enyl caprylate,methyl caproate,ethyl caproate,methyl caprate and hexyl caproate.[Conclusions]The types and contents of volatile components in fresh fruit of M.citrifolia from different origins were significantly different.

Research Progress on the Monitoring of Precursor of Atmospheric Ozone——Volatile Organic Compounds

Volatile organic compounds(VOCs)are important precursors of ozone and PM_(2.5).At present,VOCs have gradually become the focus of air pollution control after fine particles in China,and a series of documents,standards and planning on VOCs were issued from the state to each area.The analysis on source apportionment and control of VOCs have also become a hot spot in atmospheric environmental protection research of China at present stage.The research work on VOCs in ambient air is the basis and premise of scientific and effective prevention and control of VOCs pollution.In this paper,research progress on the monitoring of VOCs is introduced systemically,and main monitoring and evaluation methods of atmospheric VOCs are explored from monitoring analysis method,chemical reaction activity and health risk assessment.Moreover,concentration characteristics and source apportionment of VOCs in the regions at home and abroad that have carried out VOCs research work are compared and summarized.The research could provide reference for source apportionment of VOCs in other cities of China.

Effects of Urechis unicinctus Juveniles on Chemical Characteristics of Organically Contaminated Coastal Sediment

Biological activities of marine benthos such as burrowing and feeding may change sediment characteristics.We conducted three experiments to examine the potential of using juveniles of a spoon worm Urechis unicinctus to improve the quality of organically contaminated coastal sediment.Sediment samples were collected from a site that was heavily contaminated with organic matter (Seonso) and two sites that were clean (Myo-do,Dolsan-do).Urechis juveniles,obtained by artificial fertilization and cultured in the laboratory,were introduced to the sediment (weight 3 kg,depth 10 cm) at a density of 500 individuals per aquarium (length 50 cm,width 35 cm,height 30 cm) (Experiment 1),or at densities ranging from 100 to 900 individuals per beaker (Experiment 2).To examine how sediment contamination can be modified by the effects of Urechis,500 individuals (per aquarium) were exposed to the Seonso contaminated sediment that had been mixed with 0-100% clean sand (Experiment 3).Each experiment lasted two months and sediment samples were collected every 15 d to determine the several indexes of sediment quality,which included acid volatile sulfide (AVS),chemical oxygen demand (COD) and total ignition loss (TIL).In Experiment 1,the existence of Urechis did not result in significant changes in quality indexes in the sediments collected from Myo-do,Dolsan-do.However,AVS,COD and TIL of the Seonso sediment all decreased significantly after co-incubation with Urechis juveniles for 30 to 45 d.Experiment 2 showed that a density of at least 300 juveniles per beaker was necessary to significantly reduce all three quality indexes,and the magnitude of reduction was positively correlated with juvenile density.Experiment 3 revealed that Urechis juveniles were effective in reducing the AVS,COD and TIL of the Seonso sediment that had been mixed with 60%,80%,and 80% of clean sand,respectively.The results of the present study therefore indicated that juveniles of this spoon worm have the potential to be used to improve the quality of organically contaminated sediment in coastal waters.

Applying chemical engineering concepts to non-thermal plasma reactors

Process scale-up remains a considerable challenge for environmental applications of non-thermal plasmas.Undersanding the impact of reactor hydrodynamics in the performance of the process is a key step to overcome this challenge.In this work,we apply chemical engineering concepts to analyse the impact that different non-thermal plasma reactor configurations and regimes,such as laminar or plug flow,may have on the reactor performance.We do this in the particular context of the removal of pollutants by non-thermal plasmas,for which a simplified model is available.We generalise this model to different reactor configurations and,under certain hypotheses,we show that a reactor in the laminar regime may have a behaviour significantly different from one in the plug flow regime,often assumed in the non-thermal plasma literature.On the other hand,we show that a packed-bed reactor behaves very similarly to one in the plug flow regime.Beyond those results,the reader will find in this work a quick introduction to chemical reaction engineering concepts.

Volatiles from <i>Prunus persica</i>Flowers and Their Correlation with Flower-Visiting Insect Community in Wanbailin Ecological Garden, China

Object: To investigate the VOCs from living Prunus persica flowers of different branches and their correlation with floral insects. Special, dominant and 20 VOCs were analysed from living Prunus persica flowers captured by closely and circularly headspace way in adsorbent tubes and ATD-GC/MS on 29 April in Wanbailin Ecological Garden, China. VOCs from high altitude tree are more than low altitude in sunny site, and floral volatile constituents from upslope branches are less than downslope of the same tree on high altitude. Special floral VOCs were alpha-dimethyl-benzenemethanol, isopropyl palmitate, ethylbenzene, p-xylene, acetophenone, 3-ethyl-2-methyl-Heptane on sunny slope, and propylene glycol, decanal, hexadecane on shady slope. Dominant VOCs founded during 8 temporal quanta were toluene, hexane, 2-ethyl-1-hexanol, dodecane, pentadecane. Floral VOCs’ number from sunny slope was significantly negative correlated with flower-visiting insect community richness, abundance, diversity on sunny or shady slope, which from shady slope was significantly positive correlated with flower-visiting insect community parameters on both slopes tried dividing insects visiting floral branches from Prunus persica in sunny site with n/2 + 1 or n/2 - 1, and shady site with n/2 before sampled volatiles day. On sampled volatiles day, 2-ethyl-1-hexanol from sunny slope was significantly positive correlated with flower-visiting insect community parameters on shady slope (P Prunus persica on sunny slope, and even floral branches kept on shady slope.

云南特有“藤条茶”品质化学成分分析

云南特有的藤条茶,源于当地茶农在长期生产中创造的一种独特留采法,因能促使茶树树干形似藤条而得名。为探究藤条茶留采管理模式对茶叶品质的影响,选取藤条茶园一芽二叶鲜叶制作晒青茶、红茶、白茶,以现代茶园同类鲜叶制样为对照,结合感官审评和品质化学成分进行分析。研究表明,采用藤条茶树鲜叶制成的晒青茶一般具有更高爽的香气和浓醇的滋味,白茶则具有更浓郁的香气及甘和的滋味,而现代茶园红茶一般具有更高甜的香气和甘爽的滋味。藤条茶的儿茶素总量均显著低于现代茶园茶树鲜叶,尤其是藤条白茶中的儿茶素总量为67.11 mg·g^(-1),显著低于现代茶园白茶(84.19 mg·g^(-1))。藤条晒青茶中的茶氨酸含量为16.79 mg·g^(-1),显著高于现代茶园晒青茶(14.69 mg·g^(-1))。藤条晒青茶和藤条白茶具有更低的酚氨比。在所有茶样中共鉴定出205个初级代谢产物,藤条白茶中积累更丰富的糖类。此外,在所有茶样中检测出127种挥发性物质,醇类和酯类是不同茶样中主要的挥发性成分,藤条白茶中挥发物总量显著高于现代茶园白茶;藤条红茶中香叶醇含量更高,而现代茶园红茶的芳樟醇含量更高。可见,采用晒青茶和白茶的加工工艺一般更有利于获得高品质藤条茶产品。